The present invention relates to systems and methods for storing computer files on magnetic medium or the like and in particular to such systems and methods for storing a potentially large number of such files for archival purposes.
A wide variety of storage devices has been developed for storing digital data or information generated by and utilized in conjunction with, a digital computer. The selection of an appropriate storage device for a particular application is dictated by several factors including the cost per byte of information stored and the read/write response time. CMOS random access memories (RAM) provides the fastest response time, but has the highest cost per byte. At the other end of the spectrum, magnetic tape has the slowest response time, but the lowest cost per byte stored. This cost factor makes magnetic tape the preferred medium for archiving data files for long term storage.
Information processed by a computer is organized into distinct units called files, each of which contains related data. In addition to the data, each file commonly contains descriptive information such as the title of the file and the date of its creation or last revision. Additionally, each file contains control information specific to the operating system software with which the file is created that establishes the manner in which the operating system software processes the data. By way of example, MS DOS operating system software, which is commercially available, creates specific information used to determine if a file belongs to the system or the user. Macintosh operation system software provides information words related to Icons, colors, fonts and the like, all of which pertain to graphic display control. Unix operating system software includes specific information identifying the file type and the permissive user access to the file.
Although the file data is typically available in standard formats common to the major commercially available operating systems, the remaining information related to a file typically cannot be processed by an operating system different from that which creates the file. Not only is certain control information, which performs specific control functions, not functional with different operating systems, the format of the file name often varies in size and makeup for different operating systems. The result, is that a file created and stored on a medium by one operating system can only be read, or restored, by a computer using substantially the same operating system. While emulators have been developed that provide adaptations between different operating systems, known emulators are specific to the operating systems being adapted from and the operating system being adapted to. Whenever it is desired to include another operating system in the emulator, all prior versions must be reissued to support the new operating system.
Another difficulty with conventional systems and methods for storing files for archival purposes is the batch processing of files to storage. Thus, once archived, individual files cannot be identified and restored separate from the batch of files, which must be restored as a batch. While systems have been proposed that include a directory of individual files stored in a medium, such that a review of the files on the medium and selective restoration of individual files is available, destruction of the directory results in the inability to retrieve the associated data files.